Signaling system



Jan. 3, 1933. H'UND 1,893,029

SIGNALING SYSTEM Filed Oct. 1; 1931 INVENTOR Augu st Hunfl ATTORNEY Fatcnted Jan. 3, 1933 i itaataa i AUGUST 311KB, 01 WEST ORANGE, NEW JERSEY, 'ASSIG-NOR TO WIRED RADIO, INC 013 NEW YORK, N. Y A CORPORATION DELAWARE SIGNALING SYSTEM I Application filed October 1, 1981. Serial No. 566,229,

My invention pertains in general to signaling systemsand specifically relates to a system forefiecting the key modulation of high frequency oscillations.

In my co-pending appllcation, Serial Number 561,837, filed September 9, 1931, and

entitlted, Oscillation generator, I have dis-' closed a s stem for developing high frequency oscillations from relaxation osclllations produced by a glow discharge tube.

The principal object of my present invention consists in providing a relaxation osc llation circuit for producing high frequency oscillations for keying modulation purposes.

Another object consists in producin a relaxation system for developing higi frequency oscillations which are signal modulated by oscillations produced by another relaxation circuit.

I accomplish these and other desirable objects in a novel signaling system employing a glow discharge tube and associated circuits for producing high frequency oscillations which are modulated by relaxation oscillations produced by another glow discharge tube and associated 'circuit.

In thedrawing accompanying and forming a part of this specification I have diagrammatically represented one embodiment of the signalling system in my invention showing a preferred arrangement of the circuits.

Referring to the drawing in detail there is provided a glow discharge tube 1 which comprises a tubular envelope enclosing a pair of electrodes 2 and 3. In the presentembodiment of-my invention this envelope is provided with an attenuated atmosphere of helium. I have found that satisfactory results can be obtained by maintainingthis atmosphere of helium at a pressure of sub st'antially 12 mm; of mercury- It will be understood that other suitable gases can be used in lieu ofhelium and at other suitable presbular metallic control electrode 4 is enternally positioned on the envelope 1 in a position encircling the gap between the ends of the two electrodes 2 and 3. The electrode 4 serves to electrostatically control or modulate the ionization discharge between electrodes 2 and 3 in the glow discharge tube 1 as herewith the variable condenser 8, as shown. The

inductance 9 is electromagnetically coupled to an inductance 11.- The inductance 11 is connected in series with-a capacitance 12 and load 13 to form a resonant circuit tuned to a desired high frequency suitable for carrier transmission purposes and designated as the frequency f,. The load.13 is indicative of any work circuit for the utilization of signal modulated high frequency currents, such as an antenna system.

In accordance with my invention, there is provided another glow discharge tube 15 comprising'an envelope enclosing a pair of electrodes 16 and 17. The envelope 15 is provided with an attenuated atmosphere of helium at a pressure of substantially 12 mm. of mercury similar to the glow discharge tube 1.

The electrodes 16 and 17 are disposed in a manner such as to reduce inter-electrode capacitance to a minimum. These electrodes 16 and 17 are connected with an external circuit including a resistance 18, a source of direct current 19 and an inductance 20, all connected in series. is connected in shunt with the electrodes 16 A variable condenser 14 and 17 The inductance 20 comprises the primary winding of an audio frequency transformer having a secondary winding 21. The secondary winding 21 is connected with a key 22 ofthat type having two contacting 24, for simultaneously opening both sides of a circuit, such as the circuit between the control electrode 4 and electrode 3 of glow discharge tube 1. The actual construction of members, such as contacting members 23 and the key 22 is well-known in radio signaling and for that reason is only diagrammatically represented in the drawing.

In the operation of my signaling system, the source of current 6 applies a potential difference to the electrodes 2 and 3 which is of a magnitude sufficient to. initiate a glow or ionization dischar e. The voltage necessary to 'brin about this glow discharge will be called t e ignition vo' and 3 becomes smaller thanthe lower critical voltage, the glow discharge will be quenched. The foregoing functions will be repeated to produce continuous relaxation oscillations of a fundamental frequency designated as f These relaxation oscillations produced by the glow discharge tube 1 and associated circuit produce impulse energization of the cir cuit 9-10. The circuit 9-10 has parameters of a value such that this impulse energization will set up oscillatory currents at frequencies which will be integral multiples of the funda mental frequency f, ofthe relaxation oscillation s. The resonant circuit including the inductance 11 and capacitance 12 is tuned to a desired high frequency f whichis a particular integral multiple of the fundamental relaxation frequency f The frequency f appears in the resonant circuit 9-10 and is selected by the-circuit, 11-12 for effecting the transfer of oscillations at the desired frequency f, to the load 13.

Further in the operation of my signaling system, the source of direct current 19 applies a potential difference to the electrodes 16 and 17 which is of a magnitude suflicient to initi-v ate a glow or ionization discharge in the tube v 15. This glow discharge which takes place across electrodes 16 and 17 will produce a potential drop across the resistance 18 wherey the voltage across the electrodes 16 and 17 will become reduced. s'soon as this voltage reduction occurs the glow discharge will be quenched. The foregoing functions will then be repeated to produce continuous relaxation oscillations of an audible frequency f independently of the frequencies or f,. These oscillations of the frequency f produced by the glow discharge tube 15 act through winding 20 to induce electromotive-r -and means for selectiv associated circuit. The high frequency oscillations of the frequency f appearing in circuit 11-12 and transferred to load 13 .will therefore be audibly modulated for a duration depending upon the period of time that key 22 is manually closed. Thus, the key 22 can bemanipulated to produce signal modulation in accordance with any desired code as is'common in radio signaling.

Although I have shown a referred'eln- 'bodiment of my radio signaling system it will, of course, be understood that changes can be made therein without departing from the intended scope of my invention. I do not therefore desire to lnnit myself to the foregoing except insofar as may be pointed out in the appended claims.

What I c aim as new and 'sire to secure by Letters Patent of the United States is:

original and de-" 1. A signaling system comprising,- an OS cillation circuit for producing oscillations, a selection circuit coupled to said oscillation circuit, said selection circuit beng tuned to a desired high frequency, a relaxation circuit for recurrently energizing said oscillation circuit at a frequency which is an aliquot part of said des red frequency, a source of audible frequency oscillations, e y connecting said source of audible frequency oscillations with said relaxation circuit for effecting the modulation of said oscillations of said desired high frequency by said audible frequency oscillations.

- 2. A signaling system comprising, an osc llation circuit for producing high fre uency oscillations, a selection circuit couple said oscillation circuit, said selection circuit being tuned to a desired high frequency, a relaxation oscillation circuit for recurrently energizing said oscillation circuit at a frequency which 15 an aliquot art of said desired frequency, said relaxation oscillationcircuit including a' glow .discharge tube having an external control electrode, a resistance, and a'source of direct current all connected in series-another relaxation oscillation circuit includinga glow discharge tube, a resistance, and a source of direct current connected in series; and akeying circuit connected with said control electrode, said-keying circuit be- AUGUST HUND.

igh frequency with p ing inductively coupled with said second 7 mentioned relaxation oscillation circuit. 

